Shell Structures in Self‐Assembled InAs Quantum Dots Observed by Lateral Single Electron Tunneling Structures

The electron transport through single self‐assembled InAs quantum dots (QDs) grown on GaAs surfaces has been investigated by using metallic leads with narrow gaps. Clear Coulomb staircases and Coulomb gaps have been observed at 4.2 K. Coulomb blockade oscillation which reflects the shell filling in the QDs was also observed when a backgate voltage was swept. It is found that uncapped as‐grown InAs QDs with a diameter of approximately 50 nm contain one or two electrons.